Study on the mechanism of aflatoxin B1 degradation by Tetragenococcus halophilus
Wei Li, Wen‐Jun Li, Chao Zhang, Ning Xu, Caixia Fu, Chao Wang, Deyuan Li, Qian Wu
Abstract
The degradation conditions of aflatoxin B1 (AFB1) by T. halophilus in MRS liquid culture were studied. The inoculum amount of T. halophilus, fermentation time, and fermentation temperature were recorded as experimental factors, and the degradation rate of AFB1 was measured as the experimental index. AFB1 degradation increased with the increase of temperature, with a maximum value of 75.9 ± 4.92%. When the temperature exceeded 32 °C, the degradation rate showed a downward trend. Experimental results showed that the degradation of AFB1 by T. halophilus was related to the starting concentration of the strain. The molecular weight of the extracellular enzymes that degraded AFB1 ranged from 55 KD to 70 KD,Zn2+ can promote the activity of AFB1 degradation by this enzyme, while Al3+, Ba2+, Ca2+ and Mn2+ can inhibit the activity of AFB1 degradation by this enzyme. Especially, the inhibitory effect of Ca2+ is the strongest, up to 48.54%, and the optimal temperature is 32 °C. The degradation products of AFB1 were identified as M/Z327.08 (C17H10O7) and M/Z285.08 (C16H12O5). Taken together, these results demonstrated that T. halophilus has application potential for AFB1 degradation.